Seeing this as well on a M1 Mac

At some point this started to happen for me as well. Maybe Apple made it more complicated to retrieve GPU information.

I've also been seeing this issue on my M1 Mac

I prefer to solve the problem with code like the one below.

const isMacARM = async () => {
  try {
    const agentData = await navigator.userAgentData.getHighEntropyValues([
      "architecture",
    ]);
    return agentData.platform === "macOS" && agentData.architecture === "arm";
  } catch (e) {
    return false;
  }
};

I prefer to solve the problem with code like the one below.

const isMacARM = async () => {
  try {
    const agentData = await navigator.userAgentData.getHighEntropyValues([
      "architecture",
    ]);
    return agentData.platform === "macOS" && agentData.architecture === "arm";
  } catch (e) {
    return false;
  }
};

This does not work on Safari M2.